Tubular heat exchange element



Feb. 18, 1941. w. RIEGER TUBULAR HEAT EXCHANGE ELEMENT Filed Oct. 24.19:9

INVENTOR w/z HELM 75427? Patented Feb.18, 1941 1 2,232,272

UNITED, STATES PATENT OFFICE Wilhelm Rieger, Kassel-Wilhelmshohe,Germany, assignor to The Superheater Company, New York, N. Y.

Application October 24, 1939, Serial No. 300,941 In Germany October 12,1938 3 Claims. (01. 257-254) The present invention relates toimprovements pipes l3 and [4 may be joined by well known in tubular heatexchange elements such as those methods so as to form a breeches piecel5. Then utilized in superheaters. The invention consists instead ofclosing the end of the breeches piece essentially in providing anelement made up of as is done to fabricate a conventional type of 5 apair of parallel pipes connected for serial flow superheater element thetubes I1 and 20 are 5 by a return bend with an extension in the naturejoined as described above. The outer end of of a Field tube. tube 20 maybe closed either before or after join- The invention will best beunderstood upon ing it to the breeches piece. To extend the reference tothe following detailed description amount of heat transfer surface in anexisting when read in conjunction with the accompanyheat exchangeelement made up of parallel pipes 10 ing drawing in which connected by areturn bend, the end of the re- Fig. 1 is a vertical sectional viewthrough part turn bend is cut off transversely and the tubes of a boilerflue having therein a tubular heat exl1 and. 20 then connected asdescribed above. change element embodying the invention; What I claimis: Fig. 2 is a similar horizontal view, and l. A heat exchange elementfor use in a boiler Fig. 3 is a cross sectional view on the line 3-3flue comprising; a pair of parallel tubes; an openof Fig. l endedbreeches piece connecting said tubes at the In the drawing the numerall0 designates part ends thereof that are adapted to be located withof aboiler flue having one end connected to a in the flue; a tube having oneend extending flue sheet ll. Mounted in the flue l0 so as to throughsaid breeches piece into one of said pipes 20 be exposed to the heat ofgases travelling thereand so joined thereto that its interior forms athrough is a superheater element designated as continuation of the fluidpassage of said pipe, a whole by the numeral I2. The element l2 consaidtube being smaller in cross section than the sists of a pair of parallelmetallic pipes I3 and I4 opening in said breeches piece and projectingconnected by a breeches piece l5. Instead of befrom the latter; a secondtube closed at one end 25 ing closed to form a return bend, as in aconsurrounding the projecting portion of said first ventional loopedelement, the breeches piece 15 tube and joined at its other end to saidbreeches has an opening it at its end. A tube I! having piece about theopening in the end thereof, said an external diameter smaller than thecross secsecond tube being in communication with the intion of openingIii (so as to leave an annular pasterior of said first tube and being oflarger di- 30 sage) extends therethrough and into the pipe l3. ameter toform a passage between said tubes in In joining the tube I? to the pipel3 its end communication with the interior of the other of portion isscarfed and brought to a red heat said pipes via the space between saidfirst tube before inserting it into the pipe Hi. The tube and breechespiece and the interior of the latll projects a substantial distancebeyond the ter. 35 end of the breeches piece l5 and. is surrounded 2. Aheat exchange element for use in a boiler by a larger concentric tube 20suitably closed at flue comprising; a pair of parallel tubes; an itsouter end. Tube 20 is joined to the breeches open-ended breeches piececonnecting said tubes piece 15 about the Opening in its the end at theends thereof that are adapted to be 10:-

of the tube 20 preferably being welded to the Gated Within t flue; thaving one end 40 metal at the PehpheP-Y of the o'pemng Spac tendingthrough said breeches piece into one of mg 3 3 2 5?? be tack weld saidpipes and so joined thereto that its interior fi i g g igg g g 1 forms acontinuation of the fluid passage of said ys pipe, said tube beingsmaller in cross section than 4o with the annular space 22 between thetubes ll the 0 em said breeches iece and mm and 20. As shown herein,this is brought about f p 1 p p 1e 1 g by making the tube 20 of greaterlength than the mm tube clpsed at p end projecting portion of the tubesurrounding the pro ecting portion of said first when the element isemployed as a Superheat tube and oined at its other end to sa1d breechespiece about the opening in the end thereof, said 50 er tube, steam flowsthrough the pipe IS in the direction of the arrow and thence throughtube second tube bemg longer than sa1d first tube so H, the ann larspace 22, th space between tube that their interiors communicate andbeing of H and the wall of breeches piece l5 and from l r me r th n saidfirst tube to form a the latter into the pipe l4. passage between saidtubes communicating with In constructing new elements of this type thethe interior of the other of said pipes via the 55 said pipes and havingits end so joined to the latter that the interiors of said pipe and tubeform a continuous fiuid passage, said second tube being smaller indiameter than the opening in said ,breeches piece and projecting throughthe 5 latter to a point adjacent the closed end of said first tube sothat the interior of said one pipe conm'iunicates with that of the otherpipe via said second tube and the space between it and the first tube.

WILHELM RIEGER.

